Complementary color flashing for multichannel image presentation

ABSTRACT

Methods are provided for the highlighting of features in composite images through the alternating of images having complementary colors. An image having a feature of interest is used to generate one or more pseudo color images. A series of a pseudo color images and one or more additional pseudo color or original color images are then alternately displayed so that the differently colored regions among the series of images are easily recognizable to an operator. The differently colored regions differ in having hues that are complementary to one another. The methods are particularly useful for the display of information using two or more imaging modalities and channels, such as is the case for some medical applications in which a natural-light image of pink or light-red tissue with deeper red or blue vasculature is overlaid with another functional image. In these cases, a feature present in the functional image can be more easily perceived when displayed in a composite overlay with an underlying image from another imaging modality or channel.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/630,776, filed Jun. 22, 2017, which claims the benefit of U.S.Provisional Patent Application No. 62/353,764, filed Jun. 23, 2016, andU.S. Provisional Patent Application No. 62/425,967, filed Nov. 23, 2016,each of which is incorporated by reference in its entirety herein forall purposes.

BACKGROUND

In modern biological and medical imaging technologies, multiple imagingchannels or multiple imaging modalities are frequently used together tooffer complementary or additional information. For instance, afluorescence channel can be used together with a white light channel toidentify fluorescence signal from biological or molecular targets on topof the anatomical features presented in the white light image. Asanother example, a functional image of radioactive agents can be shownon a tomographic anatomical image, such as that produced by computedtomography (CT) or magnetic resonance imaging (MRI), to help localizediseases in a subject (U.S. Pat. No. 8,538,504; Yoshino et al. (2015) J.Radiation Res., 56:588-593).

Frequently, a pseudo-color or a color map is selected for one imagechannel so that it can better provide additional information whenvisualized on top of one or more other image channels. This concept hasbeen used in many different research areas, such as those of clinicaltranslational studies, as well as in medical care areas when applying avariety of imaging technologies.

Very often, real-time visualization is critical to enabling rapidrecognition and understanding of imaging information presented in theformat of a still frame, an animation, an augmented view, or a video.This can be particularly important when timely decision-making isrequired in response to accurate perception of a scenario via one ormore imaging modalities. With this in mind, developments have been madein not only optical collection and sensing electronics for fluorescence,but in the uses of color maps and pseudo colors as applied to overlaidimages (Elliot et al. (2015) Biomedical Optics Express, 6:3765-3782). Inmost of these scenarios, a reflective or white light image is as anunderlying image that is presented together with one or moresuperimposed or co-localized fluorescence results (U.S. Pat. Nos.7,330,749; 8,131,476).

In visualizing overlaid signals on a display, different perceptionfactors, such as those of color selection, lightness, andtransparency/alpha, can be adjusted. As human eyes are most sensitive tolightness, a fusion image can use a constant color map with changinglightness to indicate the most important scalar value, such as imagingagent concentration, targeted molecule concentration, grading, depth,severity, etc. Alternatively, a presentation scheme using a lookup tableof different color saturations or color hues can be used to indicatescalar values. Information can also be presented by relying on differingtransparency/alpha values at constant lightness and hue.

However, with these image fusion presentation schemes, it is oftendifficult for an operator to see the pseudo colors against thebackground of an underlying image. This is particularly the case whenthe underlying image channel is a true-color reflective light image or abright tomographic section of a tissue or an object, as these arefrequently characterized by large variations in color or brightness. Forexample, an underlying image can be a natural-light image of pink orlight-red tissue with deeper red or blue vasculature.

To assist in visualizing signal with minimal interference, it has beenproposed to allow a user to manually switch off one or more imagechannels, such as a reflective light channel, in order to betterrecognize the signal associated with another channel before turning theoff channels back on. Alternatively, a component of a composite picturecan be sinusoidally pulsed relative to the other elements of thecomposite picture (Glatz et al. (2014) J. Biomedical Optics, 19:040501).In this approach, the average background hue is calculated in order toguide the selection of the pulsed color. Yet these techniques can poseproblems of decreased time efficiency, reduced ease-of-use, or lowereffectiveness, particularly when presenting weak signals.

BRIEF SUMMARY

In general, provided herein are methods for displaying visualinformation by flashing complementary colors representing information ofinterest within an overlay of static images or video frames. An originalcolor of an image is replaced with one or more complementary colors.These complementary colors are then flashed in a composite image thatcan comprise multiple images depicting the same subject. Thecomplementary nature of the colors and the dynamic presentation of thecolors through flashing can improve the perception of signal areaswithin the images or frames. This in turn can maximize the transfer ofvisual information to an operator and can minimize interpretive errorsin acquiring data from the presented images.

One provided method for displaying images comprises receiving a firstimage. The first image comprises an original color and represent a viewfrom a viewpoint. The method further comprises acquiring a second image.The second image represents a view from the viewpoint. The methodfurther comprises generating a third image by replacing the originalcolor of the first image with a first false color having a first hue.The method further comprises producing a fourth image by replacing theoriginal color of the first image with a second false color having asecond hue. The second hue is complementary to the first hue. The methodfurther comprises rendering a fifth image by overlaying the third imageand the second image. The method further comprises constructing a sixthimage by overlaying the fourth image and the second image. The methodfurther comprises alternately displaying the fifth and sixth images.

In some embodiments, the first image has a minimum first image colorvalue and a maximum first image color value. In some embodiments, thefirst false color and the second false color have a false color valuethat is within the range between the minimum and maximum first imagecolor values. In some embodiments, the first false color is black andthe second false color is white.

In some embodiments, the alternately displaying is performed at afrequency. In some embodiments, the frequency of the alternatelydisplaying is between 0.1 Hz and 25 Hz.

In some embodiments, the first and second images each represent views ofa biological sample. In some embodiments, the biological sample is an invivo sample. In some embodiments, the biological sample is an ex vivosample. In some embodiments, the biological sample is from a mammaliansubject. In some embodiments, the biological sample comprises a tumor.

In some embodiments, the first image is a fluorescence image, an X-rayimage, a positron emission tomography (PET) image, a photon emissioncomputed tomography (SPECT) image, a magnetic resonance imaging (MRI)image, a nuclear magnetic resonance (NMR) image, an ultrasound image, anautoradiography image, an immunohistochemistry image, or a microscopyimage. In some embodiments, the second image is a reflected light imageor a tomography image.

In some embodiments, the first image is recorded using a first camera orimager. In some embodiments, the second image is recorder using a secondcamera or imager. In some embodiments, the first camera or imager is thesecond camera or imager.

In some embodiments, the method further comprises accepting operatorinput selecting the frequency of the alternately displaying. In someembodiments, the method further comprises accepting operator inputselecting the viewpoint.

Also provided is a method of displaying images, wherein the methodcomprises receiving a first image. The first image comprises an originalcolor and represents a view from a viewpoint. The method furthercomprises generating a second image by replacing the original color ofthe first image with a first false color having a first hue. The methodfurther comprises producing a third image by replacing the originalcolor of the first image with a second false color having a second hue.The second hue is complementary to the first hue. The method furthercomprises alternately displaying the second and third images.

In some embodiments, the first image has a minimum first image colorvalue and a maximum first image color value. In some embodiments, thefirst false color and the second false color have a false color valuethat is within the range between the minimum and maximum first imagecolor values. In some embodiments, the first false color is black andthe second false color is white.

In some embodiments, the alternately displaying is performed at afrequency. In some embodiments, the frequency of the alternatelydisplaying is between 0.1 Hz and 25 Hz.

In some embodiments, the first image represents a view of a biologicalsample. In some embodiments, the biological sample is an in vivo sample.In some embodiments, the biological sample is an ex vivo sample. In someembodiments, the biological sample is from a mammalian subject. In someembodiments, the biological sample comprises a tumor.

In some embodiments, the first image is a reflected light image, afluorescence image, an X-ray image, a PET image, a SPECT image, an MRIimage, an NMR image, an ultrasound image, an autoradiography image, animmunohistochemistry image, or a microscopy image.

In some embodiments, the method further comprises accepting operatorinput selecting the frequency of the alternately displaying. In someembodiments, the method further comprises accepting operator inputselecting the viewpoint.

Also provided is a method of displaying images, the method comprisingreceiving a first image. The first image comprises an original colorhaving a first hue and represents a view from a viewpoint. The methodfurther comprises generating a second image by replacing the originalcolor of the first image with a false color having a second hue. Thesecond hue is complementary to the first hue. The method furthercomprises alternately displaying the first and second images.

In some embodiments, the first image has a minimum first image colorvalue and a maximum first image color value. In some embodiments, thefalse color has a false color value that is within the range between theminimum and maximum first image color values. In some embodiments, oneof the original color or the false color is black, and the other of theoriginal color or the false color is white.

In some embodiments, the alternately displaying is performed at afrequency. In some embodiments, the frequency of the alternatelydisplaying is between 0.1 Hz and 25 Hz.

In some embodiments, the first image represents a view of a biologicalsample. In some embodiments, the biological sample is an in vivo sample.In some embodiments, the biological sample is an ex vivo sample. In someembodiment, the biological sample is from a mammalian subject. In someembodiments, the biological sample comprises a tumor.

In some embodiments, the first image is a reflected light image, afluorescence image, an X-ray image, a PET image, a SPECT image, an MRIimage, an NMR image, an ultrasound image, an autoradiography image, animmunohistochemistry image, or a microscopy image.

In some embodiments, the method further comprises accepting operatorinput selecting the frequency of the alternately displaying. In someembodiments, the method further comprises accepting operator inputselecting the viewpoint.

Also provided is a method of displaying images, the method comprisingreceiving a first image. The first image comprises an original colorhaving a first hue and represents a view from a viewpoint. The methodfurther comprises acquiring a second image representing a view from theviewpoint. The method further comprises generating a third image byreplacing the original color of the first image with a false colorhaving a second hue. The second hue is complementary to the first hue.The method further comprises rendering a fourth image by overlaying thethird image and the second image. The method further comprisesconstructing a fifth image by overlaying the first image and the secondimage. The method further comprises alternately displaying the fourthand fifth images.

In some embodiments, the first image has a minimum first image colorvalue and a maximum first image color value. In some embodiment, thefalse color has a false color value that is within the range between theminimum and maximum first image color values. In some embodiments, oneof the original color or the false color is black, and the other of theoriginal color or the false color is white.

In some embodiments, the alternately displaying is performed at afrequency. In some embodiments, the frequency of the alternatelydisplaying is between 0.1 Hz and 25 Hz.

In some embodiments, the first and second images each represent views ofa biological sample. In some embodiments, the biological sample is an invivo sample. In some embodiments, the biological sample is an ex vivosample. In some embodiments, the biological sample is from a mammaliansubject. In some embodiments, the biological sample comprises a tumor.

In some embodiments, the first image is a fluorescence image, an X-rayimage, a PET image, a SPECT image, an MRI image, an NMR image, anultrasound image, an autoradiography image, an immunohistochemistryimage, or a microscopy image. In some embodiments, the second image is areflected light image or a tomography image.

In some embodiments, the first image is recorded using a first camera orimager. In some embodiments, the second image is recorder using a secondcamera or imager. In some embodiments, the first camera or imager is thesecond camera or imager.

In some embodiments, the method further comprises accepting operatorinput selecting the frequency of the alternately displaying. In someembodiments, the method further comprises accepting operator inputselecting the viewpoint.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a process for alternately displaying two falsecolor images derived from a first imaging channel, each false colorimage overlaid on an image from a second imaging channel.

FIG. 2 is a schematic overview of an embodiment in accordance with theprocess of FIG. 1.

FIG. 3 is an illustration of an embodiment in accordance with theprocess of FIG. 1 and the schematic overview of FIG. 2.

FIG. 4 illustrates a hue/saturation/value (HSV) cylindrical color space.

FIG. 5 is a flowchart of a process for alternately displaying two falsecolor images derived from an imaging channel.

FIG. 6 is a schematic overview of an embodiment in accordance with theprocess of FIG. 5.

FIG. 7 is an illustration of an embodiment in accordance with theprocess of FIG. 5 and the schematic overview of FIG. 6.

FIG. 8 is a flowchart of a process for alternately displaying a falsecolor images derived from an imaging channel and an original color imagefrom the imaging channel.

FIG. 9 is a schematic overview of an embodiment in accordance with theprocess of FIG. 8.

FIG. 10 is an illustration of an embodiment in accordance with theprocess of FIG. 8 and the schematic overview of FIG. 9.

FIG. 11 is a flowchart of a process for alternately displaying a falsecolor images derived from an imaging channel and an original color imagefrom the imaging channel, each of the images overlaid on an image from asecond imaging channel.

FIG. 12 is a schematic overview of an embodiment in accordance with theprocess of FIG. 11.

DETAILED DESCRIPTION

Embodiments of the present invention relate in part to the use ofcomplementary color flashing to display information in composite images.The methods disclosed can be used to enhance visual perception ofsuperimposed data by applying complementary colors and dynamic imagechanges. Although not being bound to any particular theory, it isbelieved that a reduction of the visual sensitivity of an operator isminimized by phototransduction refreshment of human photoreceptorsthrough the viewing of complementary colors. Also, the use of dynamicstimulations with flicking or flashing frequencies takes advantage ofthe ability of the human visual system to better recognize signals thatare dynamic in nature.

Using the provided methods, overlaid pseudo-color images can be quicklyand effectively visualized and perceived to achieve the goals ofmaximizing information transfer and minimizing interpretive errors. Theperception of signal distribution in composite images can be obtained inreal-time and can be applied to multimodal or multichannel image data.

While a co-localized or superimposed static image can provide for animmediate review of overlaid signals among multiple different channels,very often the bright signal of one channel can reduce the perceivedcontrast with one or more other pseudo-colored channels. This can betrue, for example, for bright signals associate with reflectivetrue-color images, computed tomography (CT) contrast images, or X-rayimages. The use of dynamic switching of one or more pseudo colors,typically selected to be complementary in color, on a static image orvideo can enhance this perceived contrast.

The methods of superimposing a complementary pseudo-colored image on topof an underlying image can be applied, for example, to medical imageoverlays. These overlay or composite images can incorporate informationobtained from, for example, microscopy, spectral imaging, tomography,and clinical imaging. Imaging modalities can include X-ray, magneticresonance imaging (MRI), positron emission tomography (PET),single-photon emission computed tomography (SPECT), and ultrasound. Theneeds of a clinician for such overlay visualization could includepre-operative information, intra-operative and image-guided content,diagnoses and analyses, planning and management, and post-operativeverification or post-resection assessment.

FIG. 1 presents a flowchart of a process 100 for alternately displayingtwo false color images derived from a first imaging channel, each falsecolor image overlaid on an image from a second imaging channel. Inoperation 101, a first image is received, wherein the first imagecomprises an original color and wherein the first image represents aview from a viewpoint. In operation 102, a second image is acquired,wherein the second image represents a view from the viewpoint. Inoperation 103, a third image is generated by replacing the originalcolor of the first image with a first false color having a first hue. Inoperation 104, a fourth image is produced by replacing the originalcolor of the first image with a second false color having a second huethat is complementary to the first hue. In operation 105, a fifth imageis rendered by overlaying the third image and the second image. Inoperation 106, a sixth image is constructed by overlaying the fourthimage and the second image. In operation 107, the fifth and sixth imagesare alternately displayed.

FIG. 2 provides a schematic overview of one embodiment in accordancewith the process of FIG. 1. Shown are a first image 201 and a secondimage 202. A third image 203 and a fourth image 204 are each generatedor produced from the first image 201 by replacing an original color ofthe first image with a false color. The false color of the third image203 has a first hue, and the false color of the fourth image 204 has asecond hue. The second hue is complementary to the first hue. A fifthimage 205 is rendered by overlaying the third image 203 and the secondimage 202. A sixth image 206 is constructed by overlaying the fourthimage 204 and the second image 202. The fifth image 205 and the sixthimage 206 are then alternately displayed.

FIG. 3 illustrates one embodiment in accordance with the process of FIG.1 and the schematic overview of FIG. 2 as an example. Shown is a firstimage 301, which is a fluorescence image representing a biologicalsample as recorded using a fluorescence imaging channel or modality froma viewpoint. A second image 302 is a true color image representing thebiological sample as recorded using a reflected light channel ormodality from the same viewpoint. The original white color of the firstimage 301 is replaced by a false red color to generate a third image303. The original white color of the first image 301 is replaced by afalse green color to produce a fourth image 304. A fifth image 305 isrendered by overlaying the third image 303 and the second image 302. Asixth image 306 is constructed by overlaying the fourth image 304 andthe second image 302. The fifth image 305 and the sixth image 306 arethen alternately displayed. The complementarity of the red and greenhues originating from the third 303 and fourth 304 images, as well asthe dynamic presentation of the composite fifth 305 and sixth 306images, allow a user to better discern the features of the originalfluorescence image 301 when viewed simultaneously with the reflectedlight image 302. This can be particularly important in scenarios inwhich appreciating the location, shape, and edges of the fluorescentfeature relative to positions on the biological sample is important.

The first image (201, 301) can be any visual representation having afeature of interest. In some embodiments, as in FIG. 3, the first image301 is a fluorescence image of a biological sample. The first image canbe a composite image of two or more imaging modalities, of two or moresubjects and/or of two or more viewpoints. The first image can compriseinformation recorded of a physical object or scene. For example, thefirst image can be a photographic or tomographic image recorded usingone or more imaging modalities. The first image can be a representationof a physical or abstract object or scene. For example, the first imagecan be of an illustration, a sketch, a computer-generated model, or apainting. The first image can be a static image or can be a frame of avideo.

The first image (201, 301) can comprise any imaging modalities. In someembodiments, as in FIG. 3, the first image 301 comprises a fluorescenceimaging modality. The first image can comprise an imaging modality ofreflected light, X-ray, computerized tomography (CT), MRI, PET, SPECT,or ultrasound. In some embodiments, the first image comprises a singleimaging modality. In some embodiments, the first image comprises two ormore imaging modalities.

The first image (201, 301) can be received from any source. In someembodiments, the first image is retrieved from a computer memory system.In some embodiments, the first image is transmitted from a source thatcan be local or remote relative to the location of the image processingof the disclosed methods. In some embodiments, the first image is input,entered, or submitted by an operator. In some embodiments, the firstimage is recorded using a camera or imager for use with one of thedisclosed method. In some embodiments, the first image is recorded usinga camera or imager and is stored using a computer memory system prior toits being retrieved or transmitted for use with one of the disclosedmethods.

One or more cameras or imagers can be used to record the first image(201, 301). The camera or imager can be configured to capture stillimages or video or movie images. The camera or imager can be configuredto have any functional lens assembly, focal length, and exposure controlsufficient to record the first image. The camera or imager can recordthe first image using a plate or film. The camera or imager can recordthe first image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor.

The first image (201, 301) comprises one or more original colors. Insome embodiments, as in FIG. 3, the first image is a monochromaticimage. In some embodiments, the first image comprises two or morecolors. The reference to the one or more colors as being original colorsis merely to specify that the colors are original to the first image,and not necessarily original to the subject of the first image. Forexample, electromagnetic radiation emitted or reflected by a subject atwavelengths outside of the spectrum visible to human perception can berepresented by alternative visible wavelengths in a first image. In thisexample, the alternative wavelengths, while not original to the subject,are original to the first image representation of the subject, and arereferred to herein as original colors.

As another example, a first image (201, 301) may represent data orinformation not associated with a color of a physical subject. This canbe the case in representing, for example, data related to values fortemperatures, pressures, concentrations, or any other non-visualparameter. In these cases, a first image can use a color scheme in whichone or more colors are used to represent one or more different values orranges of values for the non-visual parameters. In these examples, therepresentative colors are not original to a physical subject, but areoriginal to the first image, and are referred to herein as originalcolors.

As a third example, a subject can emit or reflect electromagneticradiation at visible wavelengths while a first image (201, 301) of thesubject represents these visible colors with alternate colors. This canbe the case, for example, when small differences between one or morecolors emitted or reflected by the subject are exaggerated through theselection of an alternate color scheme. This can also be the case whenthe true colors reflected or emitted by a subject are difficult for atleast some users to perceive. This can be the case, for example, with apopulation of users having one or more types of color blindness. Inthese examples, the alternative colors, while not original to thesubject, are original to the first image representation of the subject,and are referred to herein as original colors.

The first image (201, 301) can be a view of a subject representativefrom a particular viewpoint. The view can be from any distance or anglerelative to the subject. In some embodiments, the viewpoint is as leastpartially determined by the position of a camera or imager used tocapture, record, store, or transmit the first image. In someembodiments, image manipulation is used such that the view is from aviewpoint other than the actual position of a camera or imager. Zooming,panning, or rotating functionalities can be used to alter the firstimage so that it represents a view from a different viewpoint in space.This different view can be the result of repositioning the camera orimager. The different view can be the result of selecting a differentset of information that has been previously captured, recorded, stored,or transmitted while the camera or imager was in a different position.The different view can be the result of computer processing, such aswith interpolation or extrapolation algorithms, to simulate a differentposition of the camera or imager.

The subject can be a biological sample. In some embodiments, thebiological sample is one or more organisms. The biological subject canbe one or more microscopic organisms. The biological sample can be aplant. The biological sample can be an animal. The biological sample canbe a mammal. The biological sample can be a human. In some embodiments,the biological sample is a tissue, organ, or other subsection of anorganism.

The biological sample can be an in vivo sample that is part or all ofone or more living organisms. The biological sample can be an individualliving microorganism. The biological sample can be a community of two ormore living microorganisms. The biological sample can a living plant oranimal. The biological sample can be a living mammal. The biologicalsample can be a living human. The biological sample can be a tissue,organ, or other subsection of a living human. In some embodiments, thebiological sample is a region of an animal or human undergoing asurgical or other medical operation or analysis.

The biological sample can be an ex vivo sample of a tissue, organ, orother subsection removed from a plant or animal. The biological samplecan be a tissue, organ, or other subsection removed from a mammal. Thebiological sample can be a tissue, organ, or other subsection removedfrom a human. In some embodiments, the biological sample is a resectedhuman tissue sample. In some embodiments, the biological sample is abiopsy sample extracted from a human.

The biological sample can be of a mammalian subject. The mammaliansubject can be, for example, rodent, canine, feline, equine, ovine,porcine, or a primate. The mammalian subject can be human.

The subject can be a patient suffering from a disease. In someembodiments, the subject is a cancer patient. In certain aspects, thebiological sample comprises a tumor, such as tumor tissue or cells. Incertain aspects, the biological sample comprises a peripheral biopsy ofa tissue sample previously removed. In another aspect, the biologicalsample is tumor tissue such as a breast core biopsy. The biologicalsample size can be as small as a tissue slice.

The second image (202, 302) can be any visual representation from thesame one or more viewpoints as that of the first image. In someembodiments, as in FIG. 3, the second image 302 is a reflected lightimage of a biological sample. The second image can be a composite imageof two or more imaging modalities, of two or more subjects and/or of twoor more viewpoints. The second image can comprise information recordedof a physical object or scene. For example, the second image can be aphotographic or tomographic image recorded using one or more imagingmodalities. The second image can be a representation of a physical orabstract object or scene. For example, the second image can be of anillustration, a sketch, a computer-generated model, or a painting. Thesecond image can be a static image or can be a frame of a video.

The second image (202, 302) can comprise any imaging modalities. In someembodiments, as in FIG. 3, the second image 302 comprises a reflectedlight imaging modality. The second image can comprise an imagingmodality of fluorescence, X-ray, CT, MRI, PET, SPECT, or ultrasound. Insome embodiments, the second image comprises a single imaging modality.In some embodiments, the second image comprises two or more imagingmodalities.

The second image (202, 302) can be received from any source. In someembodiments, the second image is retrieved from a computer memorysystem. In some embodiments, the second image is transmitted from asource that can be local or remote relative to the location of the imageprocessing of the disclosed methods. In some embodiments, the secondimage is input, entered, or submitted by an operator. In someembodiments, the second image is recorded using a camera or imager foruse with one of the disclosed method. In some embodiments, the secondimage is recorded using a camera or imager and is stored using acomputer memory system prior to its being retrieved or transmitted foruse with one of the disclosed methods.

One or more cameras or imagers can be used to record the second image(202, 302). The camera or imager can be configured to capture stillimages or video or movie images. The camera or imager can be configuredto have any functional lens assembly, focal length, and exposure controlsufficient to record the second image. The camera or imager can recordthe second image using a plate or film. The camera or imager can recordthe second image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor. In some embodiments, the samecamera or imager is used to record or capture both the first (201, 301)and second image. In some embodiments, a first camera or imager is usedto record or capture the first image, and a second camera or imager isused to record or capture the second image.

The third image (203, 303) is generated from the first image (201, 301)by replacing one or more selected original colors from the first imagewith one or more false colors. In some embodiments, one original colorfrom the first image is replaced with one false color in generating thethird image. In some embodiments, two or more original colors from thefirst image are each replaced with one false color in generating thethird image.

The generation of the third image (203, 303) can comprise the use of acomputer system and a computation algorithm to replace the one or moreselected original colors from the first image (201, 301). In someembodiments, the third image is stored subsequent to its generation andprior to its use in rendering the fifth image (205, 305). In someembodiments, the third image is used to render the fifth image directlyafter the generation of the third image.

The false color used to replace the selected original color of the firstimage (201, 301) can be chosen to maximize contrast relative to otheroriginal colors of the first image. For example, if the first image isassociated with a surgical wound bed or a surgical tissue, then a greencolor or blue color can be chosen as the false color. In this case, thegreen or blue false color provides relatively better contrast with thered color tones typically present in images of this subject type.

Without being bound to any particular theory, the benefits ofcontrast-enhanced visual perception are likely to rely at least in parton the fundamental biophysics of photoreceptors in human visual system.In forming photo and color responses, photoreceptor cells are key partsof the visual phototransduction process. This process is used by thevisual system to convert visible light to electrical signals that aretransmitted to the visual cortex for processing into a visual image. Thetwo classic photoreceptor cells are rod and cone cells, each usinglight-sensitive photoreceptor opsin proteins. The rods are sensitive tolow light due to rhodopsin, one type of opsins, and particularlycontribute to visual formation at low light levels. The cone cells areof three types, each with different photopsins. These react mostly tothree different ranges of light bands having short, medium, and longfrequencies. The three types of cones are thus sensitive to red, green,and blue bands with peaks at about 564-580 nm, 534-545 nm, and 420-440nm, respectively. The cone cells are integral to color visual perceptionas well as motion information processed at the visual cortex. Whenexpose to visible light, these photoreceptor cells are subject tooverstimulation and can lose sensitivity in very short period of timedue to tapering of the signal transduction in the photoreceptors evenbefore fatigue occurs (such as afterimage). The use of complementarycolors can work to alleviate this overstimulation and loss ofsensitivity, and to enhance the perception of contrast.

The false color of the third image (203, 303) used to replace theselected original color of the first image (201, 301) can be chosen tohave a selected hue, saturation, or value. The properties of colors canbe described using several different parameters, including hue, chroma,purity, saturation, intensity, vividness, value, transparency,lightness, brightness, and darkness. One technique for describing colorsis through the use of the three dimensions of hue, saturation, andvalue. These three dimensions can be visualized in cylindrical orconical models.

FIG. 4 illustrates a hue/saturation/value (HSV) cylindrical model colorspace. In this representation, different angular positions representdifferent color hues. Hue is the color property defined as degree towhich a color is similar to a defined element of a color spectrum. Thesedefined elements are typically referred to as pure hues of red, orange,yellow, green, blue, and purple or violet. Different radial distanceswithin the model represent different color saturations. Colorsaturation, or color chroma, is the color property defined as the purityof a hue related to its dilution by white, gray, or black. Differentheight positions within the cylindrical space represent different colorvalues. Color value is the color property defined as indicating thelightness or darkness of a color.

Other color spaces that can be used to define and select colors for usewith the disclosed methods include International Commission onIllumination (CIE) models (such as CIE 1931 XYZ, CIELUV, CIELAB, andCIEUVW), red/green/blue (RGB) models (such as RGB, sRGB, Adobe RGB, andAdobe Wide Gamut RGB), luma plus chroma models (such as YIQ, YUV, YDbDr,YPbPr, YVbCr, and xvYCC), hue/saturation/lightness (HSL) models, andcyan/magenta/yellow/key (CMYK) models. Additive or subtractive colormodels can be used.

In some embodiments, the false color of the third image (203, 303) ischosen to have a color hue complementary to that of the selectedoriginal color of the first image (201, 301). Colors with complementaryhues are those that are on opposite sides of the HSV color space as inthe radial direction of the color model of FIG. 4. In some embodiments,the false color of the third image is chosen to have a color saturationdifferent from that of the selected original color of the first image.In some embodiments, the false color of the third image is chosen tohave a color value different from that of the selected original color ofthe first image. In some embodiments, the false color of the third imageis chosen to have a color value that is within the range between themaximum and minimum color values of all original colors of the firstimage. In some embodiments, the false color of the third image is chosento have a transparency such that it does not block relevant informationof the second image (202, 302) upon rendering of the composite fifthimage (205, 305).

The production of the fourth image (204, 304) can comprise the use of acomputer system and a computation algorithm to replace the one or moreselected original colors from the first image (201, 301). In someembodiments, the fourth image is stored subsequent to its generation andprior to its use in rendering the sixth image (206, 306). In someembodiments, the fourth image is used to render the sixth image directlyafter the generation of the fourth image.

The false color used to replace the selected original color of the firstimage (201, 301) can be chosen to maximize contrast relative to thefalse color of the third image (203, 303). For example, in FIG. 3, thefalse color of the third image 303 has a red hue and the false color ofthe fourth image 304 has the complementary green hue. As anotherexample, if the false color of the third image has a blue hue, then thefalse color of the fourth image can be selected to have a yellow hue. Ifthe false color of the third image has a green hue, then the false colorof the fourth image can be selected to have a red hue. If the falsecolor of the third image has a yellow hue, then the false color of thefourth image can be selected to have a blue hue. If the false color ofthe third image is white, then the false color of the fourth image canbe selected to be black. If the false color of the third image is black,then the false color of the fourth image can be selected to be white.

In some embodiments, the false color of the fourth image (204, 304) ischosen to have a color hue complementary to that of the false color ofthe third image (203, 303). In some embodiments, the false color of thefourth image is chosen to have a color saturation different from that ofthe false color of the third image. In some embodiments, the false colorof the fourth image is chosen to have a color value different from thatof the false color of the third image. In some embodiments, the falsecolor of the fourth image is chosen to have a color value that is withinthe range between the maximum and minimum color values of all originalcolors of the first image (201, 301). In some embodiments, the falsecolor of the fourth image is chosen to have a transparency such that itdoes not block relevant information of the second image (202, 302) uponrendering of the composite sixth image (206, 306). In some embodiments,the transparency of the false colors of the third and fourth images aresimilar or identical.

In some embodiments, green and red hues are selected for the falsecolors of the third (203, 303) and fourth images (204, 304). In someembodiments, the red hue of one of the false colors is very close to thepredominant hue of the underlying tissue that is the subject of theimages. However, even in these embodiments the complementary colorcombination refreshes the visual photoreceptors and the dynamic flashingmotion enhances the recognition sensitivity of the visual system.

The rendering of the fifth image (205, 305) is accomplished byoverlaying the second image (202, 302) and the third image (203, 303).In some embodiments, the fifth image is a composite image that is storedsubsequent to its rendering and prior to its displaying. In someembodiments, the fifth image is rendered with the use of a computersystem and computational algorithm to digitally combine the second imageand the third image in creating a fifth image. In some embodiments, thefifth image is rendered by simultaneously displaying the second imageand the third image to create a superimposed fifth image.

The constructing of the sixth image (206, 306) is accomplished byoverlaying the second image (202, 302) and the fourth image (204, 304).In some embodiments, the sixth image is a composite image that is storedsubsequent to its rendering and prior to its displaying. In someembodiments, the sixth image is constructed with the use of a computersystem and computational algorithm to digitally combine the second imageand the fourth image in creating a sixth image. In some embodiments, thesixth image is constructed by simultaneously displaying the second imageand the fourth image to create a superimposed sixth image.

The fifth (205, 305) and sixth (206, 306) images are alternatelypresented on a display for viewing by the operator. The display can be amonitor, a screen, a detector, an eyepiece, or any other visualinterface. The alternating display can dynamically enhance perceivedcontrast to help the human visual system better detect the signal andlocation of the flashing or flicking region of alternating color. Thiscan be particularly important for cases in which a low signal levelwould result in a contrast within a static image that would bechallenging for a user to ascertain with a required degree of certainty.In these cases, the flashing of complementary colors works to alleviatevisual overstimulation and loss of sensitivity, and to enhance perceivedcontrast.

FIG. 5 presents a flowchart of a process 500 for alternately displayingtwo false color images derived from an imaging channel. In operation501, a first image is received, wherein the first image comprises anoriginal color and wherein the first image represents a view from aviewpoint. In operation 502, a second image is generated by replacingthe original color of the first image with a first false color having afirst hue. In operation 503, a third image is produced by replacing theoriginal color of the first image with a second false color having asecond hue that is complementary to the first hue. In operation 504, thesecond and third images are alternately displayed.

FIG. 6 provides a schematic overview of one embodiment in accordancewith the process of FIG. 5. Shown is a first image 601. A second image602 and a third image 603 are each generated or produced from the firstimage 601 by replacing an original color of the first image with a falsecolor. The false color of the second image 602 has a first hue, and thefalse color of the third image 603 has a second hue. The second image602 and the third image 603 are then alternately displayed.

FIG. 7 illustrates one embodiment in accordance with the process of FIG.5 and the schematic overview of FIG. 6 as an example. Shown is a firstimage 701, which is a fluorescence image representing a biologicalsample as recorded using a fluorescence imaging channel or modality froma viewpoint. The original white color of the first image 701 is replacedby a false red color to generate a second image 702. The original whitecolor of the first image 701 is replaced by a false green color toproduce a third image 703. The second image 702 and the third image 703are then alternately displayed. The complementarity of the red and greenhues of the second 702 and third 703 images, as well as the dynamicpresentation of the second and third images, allow a user to betterdiscern the features of the original fluorescence image 701.

The first image (601, 701) can be any visual representation having afeature of interest. In some embodiments, as in FIG. 7, the first image701 is a fluorescence image of a biological sample. The first image canbe a composite image of two or more imaging modalities, of two or moresubjects and/or of two or more viewpoints. The first image can compriseinformation recorded of a physical object or scene. For example, thefirst image can be a photographic or tomographic image recorded usingone or more imaging modalities. The first image can be a representationof a physical or abstract object or scene. For example, the first imagecan be of an illustration, a sketch, a computer-generated model, or apainting. The first image can be a static image or can be a frame of avideo.

The first image (601, 701) can comprise any imaging modalities. In someembodiments, as in FIG. 7, the first image 701 comprises a fluorescenceimaging modality. The first image can comprise an imaging modality ofreflected light, X-ray, CT, MRI, PET, SPECT, or ultrasound. In someembodiments, the first image comprises a single imaging modality. Insome embodiments, the first image comprises two or more imagingmodalities.

The first image (601, 701) can be received from any source. In someembodiments, the first image is retrieved from a computer memory system.In some embodiments, the first image is transmitted from a source thatcan be local or remote relative to the location of the image processingof the disclosed methods. In some embodiments, the first image is input,entered, or submitted by an operator. In some embodiments, the firstimage is recorded using a camera or imager for use with one of thedisclosed method. In some embodiments, the first image is recorded usinga camera or imager and is stored using a computer memory system prior toits being retrieved or transmitted for use with one of the disclosedmethods.

One or more cameras or imagers can be used to record the first image(601, 701). The camera or imager can be configured to capture stillimages or video or movie images. The camera or imager can be configuredto have any functional lens assembly, focal length, and exposure controlsufficient to record the first image. The camera or imager can recordthe first image using a plate or film. The camera or imager can recordthe first image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor.

The first image (601, 701) comprises one or more original colors. Insome embodiments, as in FIG. 7, the first image is a monochromaticimage. In some embodiments, the first image comprises two or morecolors. The reference to the one or more colors as being original colorsis merely to specify that the colors are original to the first image,and not necessarily original to the subject of the first image. Forexample, electromagnetic radiation emitted or reflected by a subject atwavelengths outside of the spectrum visible to human perception can berepresented by alternative visible wavelengths in a first image. In thisexample, the alternative wavelengths, while not original to the subject,are original to the first image representation of the subject, and arereferred to herein as original colors.

As another example, a first image (601, 701) may represent data orinformation not associated with a color of a physical subject. This canbe the case in representing, for example, data related to values fortemperatures, pressures, concentrations, or any other non-visualparameter. In these cases, a first image can use a color scheme in whichone or more colors are used to represent one or more different values orranges of values for the non-visual parameters. In these examples, therepresentative colors are not original to a physical subject, but areoriginal to the first image, and are referred to herein as originalcolors.

As a third example, a subject can emit or reflect electromagneticradiation at visible wavelengths while a first image (601, 701) of thesubject represents these visible colors with alternate colors. This canbe the case, for example, when small differences between one or morecolors emitted or reflected by the subject are exaggerated through theselection of an alternate color scheme. This can also be the case whenthe true colors reflected or emitted by a subject are difficult for atleast some users to perceive. This can be the case, for example, with apopulation of users having one or more types of color blindness. Inthese examples, the alternative colors, while not original to thesubject, are original to the first image representation of the subject,and are referred to herein as original colors.

The first image (601, 701) can be a view of a subject representativefrom a particular viewpoint. The view can be from any distance or anglerelative to the subject. In some embodiments, the viewpoint is as leastpartially determined by the position of a camera or imager used tocapture, record, store, or transmit the first image. In someembodiments, image manipulation is used such that the view is from aviewpoint other than the actual position of a camera or imager. Zooming,panning, or rotating functionalities can be used to alter the firstimage so that it represents a view from a different viewpoint in space.This different view can be the result of repositioning the camera orimager. The different view can be the result of selecting a differentset of information that has been previously captured, recorded, stored,or transmitted while the camera or imager was in a different position.The different view can be the result of computer processing, such aswith interpolation or extrapolation algorithms, to simulate a differentposition of the camera or imager.

The second image (602, 702) is generated from the first image (601, 701)by replacing one or more selected original colors from the first imagewith one or more false colors. In some embodiments, one original colorfrom the first image is replaced with one false color in generating thesecond image. In some embodiments, two or more original colors from thefirst image are each replaced with one false color in generating thesecond image. The generation of the second image can comprise the use ofa computer system and a computation algorithm to replace the one or moreselected original colors from the first image.

The false color used to replace the selected original color of the firstimage (601, 701) can be chosen to maximize contrast relative to otheroriginal colors of the first image. For example, if the first image isassociated with a surgical wound bed or a surgical tissue, then a greencolor or blue color can be chosen as the false color. In this case, thegreen or blue false color provides relatively better contrast with thered color tones typically present in images of this subject type.

The false color of the second image (602, 702) used to replace theselected original color of the first image (601, 701) can be chosen tohave a selected hue, saturation, or value. In some embodiments, thefalse color of the second image is chosen to have a color huecomplementary to that of the selected original color of the first image.In some embodiments, the false color of the second image is chosen tohave a color saturation different from that of the selected originalcolor of the first image. In some embodiments, the false color of thesecond image is chosen to have a color value different from that of theselected original color of the first image. In some embodiments, thefalse color of the second image is chosen to have a color value that iswithin the range between the maximum and minimum color values of alloriginal colors of the first image.

The production of the third image (603, 703) can comprise the use of acomputer system and a computation algorithm to replace the one or moreselected original colors from the first image (601, 701). The falsecolor used to replace the selected original color of the first image canbe chosen to maximize contrast relative to the false color of the secondimage (602, 702). For example, in FIG. 7, the false color of the secondimage 702 has a red hue and the false color of the third image 703 hasthe complementary green hue. As another example, if the false color ofthe second image has a blue hue, then the false color of the third imagecan be selected to have a yellow hue. If the false color of the secondimage has a green hue, then the false color of the third image can beselected to have a red hue. If the false color of the second image has ayellow hue, then the false color of the third image can be selected tohave a blue hue. If the false color of the second image is white, thenthe false color of the third image can be selected to be black. If thefalse color of the second image is black, then the false color of thethird image can be selected to be white.

In some embodiments, the false color of the third image (603, 703) ischosen to have a color hue complementary to that of the false color ofthe second image (602, 702). In some embodiments, the false color of thethird image is chosen to have a color saturation different from that ofthe false color of the second image. In some embodiments, the falsecolor of the third image is chosen to have a color value different fromthat of the false color of the second image. In some embodiments, thefalse color of the third image is chosen to have a color value that iswithin the range between the maximum and minimum color values of alloriginal colors of the first image (601, 701).

The second (602, 702) and third (603, 703) images are alternatelypresented on a display for viewing by the operator. The display can be amonitor, a screen, a detector, an eyepiece, or any other visualinterface. The alternating display can dynamically enhance perceivedcontrast to help the human visual system better detect the signal andlocation of the flashing or flicking region of alternating color. Thiscan be particularly important for cases in which a low signal levelwould result in a contrast within a static image that would bechallenging for a user to ascertain with a required degree of certainty.In these cases, the flashing of complementary colors works to alleviatevisual overstimulation and loss of sensitivity, and to enhance perceivedcontrast.

FIG. 8 presents a flowchart of a process 800 for alternately displayinga false color image derived from an imaging channel and an originalcolor image from the imaging channel. In operation 801, a first image isreceived, wherein the first image comprises an original color having afirst hue and wherein the first image represents a view from aviewpoint. In operation 802, a second image is generated by replacingthe original color of the first image with a false color having a secondhue that is complementary to the first hue. In operation 803, the firstand second images are alternately displayed.

FIG. 9 provides a schematic overview of one embodiment in accordancewith the process of FIG. 8. Shown is a first image 901 having anoriginal color having a first hue. A second image 902 is generated orproduced from the first image 901 by replacing the original color of thefirst image with a false color having a second hue. The first image 901and the second image 902 are then alternately displayed.

FIG. 10 illustrates one embodiment in accordance with the process ofFIG. 8 and the schematic overview of FIG. 9 as an example. Shown is afirst image 1001, which is a PET-MRI fusion image representing abiological sample as recorded using both a PET imaging channel ormodality and an MRI imaging channel or modality, each from the sameviewpoint. The original red color of the first image 1001 is replaced bya false green color to generate a second image 1002. The first image1001 and the second image 1002 are then alternately displayed. Thecomplementarity of the red and green hues of the first 1001 and second1002 images, as well as the dynamic presentation of the first and secondimages, allow a user to better discern the features of the originalPET-MRI image 1001.

The first image (901, 1001) can be any visual representation having afeature of interest. In some embodiments, as in FIG. 10, the first image1001 is a PET-MRI fusion image of a biological sample. The first imagecan be a composite image of two or more imaging modalities, of two ormore subjects and/or of two or more viewpoints. The first image cancomprise information recorded of a physical object or scene. Forexample, the first image can be a photographic or tomographic imagerecorded using one or more imaging modalities. The first image can be arepresentation of a physical or abstract object or scene. For example,the first image can be of an illustration, a sketch, acomputer-generated model, or a painting. The first image can be a staticimage or can be a frame of a video.

The first image (901, 1001) can comprise any imaging modalities. In someembodiments, as in FIG. 10, the first image 1001 comprises both a PETimaging modality and an MRI imaging modality. The first image cancomprise an imaging modality of reflected light, X-ray, computerizedtomography (CT), fluorescence, SPECT, or ultrasound. In someembodiments, the first image comprises a single imaging modality. Insome embodiments, the first image comprises two or more imagingmodalities.

The first image (901, 1001) can be received from any source. In someembodiments, the first image is retrieved from a computer memory system.In some embodiments, the first image is transmitted from a source thatcan be local or remote relative to the location of the image processingof the disclosed methods. In some embodiments, the first image is input,entered, or submitted by an operator. In some embodiments, the firstimage is recorded using a camera or imager for use with one of thedisclosed method. In some embodiments, the first image is recorded usinga camera or imager and is stored using a computer memory system prior toits being retrieved or transmitted for use with one of the disclosedmethods.

One or more cameras or imagers can be used to record the first image(901, 1001). The camera or imager can be configured to capture stillimages or video or movie images. The camera or imager can be configuredto have any functional lens assembly, focal length, and exposure controlsufficient to record the first image. The camera or imager can recordthe first image using a plate or film. The camera or imager can recordthe first image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor.

The first image (901, 1001) comprises one or more original colors. Insome embodiments, the first image is a monochromatic image. In someembodiments, as in FIG. 10, the first image comprises two or morecolors. The reference to the one or more colors as being original colorsis merely to specify that the colors are original to the first image,and not necessarily original to the subject of the first image. Forexample, electromagnetic radiation emitted or reflected by a subject atwavelengths outside of the spectrum visible to human perception can berepresented by alternative visible wavelengths in a first image. In thisexample, the alternative wavelengths, while not original to the subject,are original to the first image representation of the subject, and arereferred to herein as original colors.

As another example, a first image (901, 1001) may represent data orinformation not associated with a color of a physical subject. This canbe the case in representing, for example, data related to values fortemperatures, pressures, concentrations, or any other non-visualparameter. In these cases, a first image can use a color scheme in whichone or more colors are used to represent one or more different values orranges of values for the non-visual parameters. In these examples, therepresentative colors are not original to a physical subject, but areoriginal to the first image, and are referred to herein as originalcolors.

As a third example, a subject can emit or reflect electromagneticradiation at visible wavelengths while a first image (901, 1001) of thesubject represents these visible colors with alternate colors. This canbe the case, for example, when small differences between one or morecolors emitted or reflected by the subject are exaggerated through theselection of an alternate color scheme. This can also be the case whenthe true colors reflected or emitted by a subject are difficult for atleast some users to perceive. This can be the case, for example, with apopulation of users having one or more types of color blindness. Inthese examples, the alternative colors, while not original to thesubject, are original to the first image representation of the subject,and are referred to herein as original colors.

The first image (901, 1001) can be a view of a subject representativefrom a particular viewpoint. The view can be from any distance or anglerelative to the subject. In some embodiments, the viewpoint is as leastpartially determined by the position of a camera or imager used tocapture, record, store, or transmit the first image. In someembodiments, image manipulation is used such that the view is from aviewpoint other than the actual position of a camera or imager. Zooming,panning, or rotating functionalities can be used to alter the firstimage so that it represents a view from a different viewpoint in space.This different view can be the result of repositioning the camera orimager. The different view can be the result of selecting a differentset of information that has been previously captured, recorded, stored,or transmitted while the camera or imager was in a different position.The different view can be the result of computer processing, such aswith interpolation or extrapolation algorithms, to simulate a differentposition of the camera or imager.

The second image (902, 1002) is generated from the first image (901,1001) by replacing one or more selected original colors from the firstimage with one or more false colors. In some embodiments, one originalcolor from the first image is replaced with one false color ingenerating the second image. In some embodiments, two or more originalcolors from the first image are each replaced with one false color ingenerating the second image. The generation of the second image cancomprise the use of a computer system and a computation algorithm toreplace the one or more selected original colors from the first image.

The false color used to replace the selected original color of the firstimage (901, 1001) can be chosen to maximize contrast relative to otheroriginal colors of the first image. For example, if the first image isassociated with a surgical wound bed or a surgical tissue, then a greencolor or blue color can be chosen as the false color. In this case, thegreen or blue false color provides relatively better contrast with thered color tones typically present in images of this subject type.

The false color of the second image (902, 1002) used to replace theselected original color of the first image (901, 1001) can be chosen tohave a selected hue, saturation, or value. In some embodiments, thefalse color of the second image is chosen to have a color huecomplementary to that of the selected original color of the first image.In some embodiments, the false color of the second image is chosen tohave a color saturation different from that of the selected originalcolor of the first image. In some embodiments, the false color of thesecond image is chosen to have a color value different from that of theselected original color of the first image. In some embodiments, thefalse color of the second image is chosen to have a color value that iswithin the range between the maximum and minimum color values of alloriginal colors of the first image.

The first (901, 1001) and second (902, 1002) images are alternatelypresented on a display for viewing by the operator. The display can be amonitor, a screen, a detector, an eyepiece, or any other visualinterface. The alternating display can dynamically enhance perceivedcontrast to help the human visual system better detect the signal andlocation of the flashing or flicking region of alternating color. Thiscan be particularly important for cases in which a low signal levelwould result in a contrast within a static image that would bechallenging for a user to ascertain with a required degree of certainty.In these cases, the flashing of complementary colors works to alleviatevisual overstimulation and loss of sensitivity, and to enhance perceivedcontrast.

FIG. 11 presents a flowchart of a process 1100 for alternatelydisplaying a false color image derived from a first imaging channel andan original color image derived from the imaging channel, each of theimages overlaid on an image from a second imaging channel. In operation1101, a first image is received, wherein the first image comprises anoriginal color having a first hue and wherein the first image representsa view from a viewpoint. In operation 1102, a second image is acquired,wherein the second image represents a view from the viewpoint. Inoperation 1103, a third image is generated by replacing the originalcolor of the first image with a false color having a second hue that iscomplementary to the first hue. In operation 1104, a fourth image isrendered by overlaying the third image and the second image. Inoperation 1105, a fifth image is constructed by overlaying the firstimage and the second image. In operation 1106, the fourth and fifthimages are alternately displayed.

FIG. 12 provides a schematic overview of one embodiment in accordancewith the process of FIG. 1. Shown are a first image 1201 and a secondimage 1202. A third image 1203 is generated from the first image 1201 byreplacing an original color of the first image with a false color. Theoriginal color of the first image 1201 has a first hue, and the falsecolor of the third image 1203 has a second hue. The second hue iscomplementary to the first hue. A fourth image 1204 is rendered byoverlaying the third image 1203 and the second image 1202. A fifth image1205 is constructed by overlaying the first image 1201 and the secondimage 1202. The fourth image 1204 and the fifth image 1205 are thenalternately displayed.

The first image 1201 can be any visual representation having a featureof interest. The first image can be a composite image of two or moreimaging modalities, of two or more subjects and/or of two or moreviewpoints. The first image can comprise information recorded of aphysical object or scene. For example, the first image can be aphotographic or tomographic image recorded using one or more imagingmodalities. The first image can be a representation of a physical orabstract object or scene. For example, the first image can be of anillustration, a sketch, a computer-generated model, or a painting. Thefirst image can be a static image or can be a frame of a video.

The first image 1201 can comprise any imaging modalities. The firstimage can comprise an imaging modality of reflected light, X-ray, CT,fluorescence, MRI, PET, SPECT, or ultrasound. In some embodiments, thefirst image comprises a single imaging modality. In some embodiments,the first image comprises two or more imaging modalities.

The first image 1201 can be received from any source. In someembodiments, the first image is retrieved from a computer memory system.In some embodiments, the first image is transmitted from a source thatcan be local or remote relative to the location of the image processingof the disclosed methods. In some embodiments, the first image is input,entered, or submitted by an operator. In some embodiments, the firstimage is recorded using a camera or imager for use with one of thedisclosed method. In some embodiments, the first image is recorded usinga camera or imager and is stored using a computer memory system prior toits being retrieved or transmitted for use with one of the disclosedmethods.

One or more cameras or imagers can be used to record the first image1201. The camera or imager can be configured to capture still images orvideo or movie images. The camera or imager can be configured to haveany functional lens assembly, focal length, and exposure controlsufficient to record the first image. The camera or imager can recordthe first image using a plate or film. The camera or imager can recordthe first image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor.

The first image 1201 comprises one or more original colors. In someembodiments, the first image is a monochromatic image. In someembodiments, the first image comprises two or more colors. The referenceto the one or more colors as being original colors is merely to specifythat the colors are original to the first image, and not necessarilyoriginal to the subject of the first image. For example, electromagneticradiation emitted or reflected by a subject at wavelengths outside ofthe spectrum visible to human perception can be represented byalternative visible wavelengths in a first image. In this example, thealternative wavelengths, while not original to the subject, are originalto the first image representation of the subject, and are referred toherein as original colors.

As another example, a first image 1201 may represent data or informationnot associated with a color of a physical subject. This can be the casein representing, for example, data related to values for temperatures,pressures, concentrations, or any other non-visual parameter. In thesecases, a first image can use a color scheme in which one or more colorsare used to represent one or more different values or ranges of valuesfor the non-visual parameters. In these examples, the representativecolors are not original to a physical subject, but are original to thefirst image, and are referred to herein as original colors.

As a third example, a subject can emit or reflect electromagneticradiation at visible wavelengths while a first image 1201 of the subjectrepresents these visible colors with alternate colors. This can be thecase, for example, when small differences between one or more colorsemitted or reflected by the subject are exaggerated through theselection of an alternate color scheme. This can also be the case whenthe true colors reflected or emitted by a subject are difficult for atleast some users to perceive. This can be the case, for example, with apopulation of users having one or more types of color blindness. Inthese examples, the alternative colors, while not original to thesubject, are original to the first image representation of the subject,and are referred to herein as original colors.

The first image 1201 can be a view of a subject representative from aparticular viewpoint. The view can be from any distance or anglerelative to the subject. In some embodiments, the viewpoint is as leastpartially determined by the position of a camera or imager used tocapture, record, store, or transmit the first image. In someembodiments, image manipulation is used such that the view is from aviewpoint other than the actual position of a camera or imager. Zooming,panning, or rotating functionalities can be used to alter the firstimage so that it represents a view from a different viewpoint in space.This different view can be the result of repositioning the camera orimager. The different view can be the result of selecting a differentset of information that has been previously captured, recorded, stored,or transmitted while the camera or imager was in a different position.The different view can be the result of computer processing, such aswith interpolation or extrapolation algorithms, to simulate a differentposition of the camera or imager.

The second image 1202 can be any visual representation from the same oneor more viewpoints as that of the first image. The second image can be acomposite image of two or more imaging modalities, of two or moresubjects and/or of two or more viewpoints. The second image can compriseinformation recorded of a physical object or scene. For example, thesecond image can be a photographic or tomographic image recorded usingone or more imaging modalities. The second image can be a representationof a physical or abstract object or scene. For example, the second imagecan be of an illustration, a sketch, a computer-generated model, or apainting. The second image can be a static image or can be a frame of avideo.

The second image 1202 can comprise any imaging modalities. The secondimage can comprise an imaging modality of reflected light, fluorescence,X-ray, CT, MRI, PET, SPECT, or ultrasound. In some embodiments, thesecond image comprises a single imaging modality. In some embodiments,the second image comprises two or more imaging modalities.

The second image 1202 can be received from any source. In someembodiments, the second image is retrieved from a computer memorysystem. In some embodiments, the second image is transmitted from asource that can be local or remote relative to the location of the imageprocessing of the disclosed methods. In some embodiments, the secondimage is input, entered, or submitted by an operator. In someembodiments, the second image is recorded using a camera or imager foruse with one of the disclosed method. In some embodiments, the secondimage is recorded using a camera or imager and is stored using acomputer memory system prior to its being retrieved or transmitted foruse with one of the disclosed methods.

One or more cameras or imagers can be used to record the second image1202. The camera or imager can be configured to capture still images orvideo or movie images. The camera or imager can be configured to haveany functional lens assembly, focal length, and exposure controlsufficient to record the second image. The camera or imager can recordthe second image using a plate or film. The camera or imager can recordthe second image using an electronic image sensor. The camera or imagercan comprise a charged coupled device (CCD) and/or a complementarymetal-oxide-semiconductor (CMOS) sensor. In some embodiments, the samecamera or imager is used to record or capture both the first 1201 andsecond image. In some embodiments, a first camera or imager is used torecord or capture the first image, and a second camera or imager is usedto record or capture the second image.

The third image 1203 is generated from the first image 1201 by replacingone or more selected original colors from the first image with one ormore false colors. In some embodiments, one original color from thefirst image is replaced with one false color in generating the thirdimage. In some embodiments, two or more original colors from the firstimage are each replaced with one false color in generating the thirdimage.

The generation of the third image 1203 can comprise the use of acomputer system and a computation algorithm to replace the one or moreselected original colors from the first image 1201. In some embodiments,the third image is stored subsequent to its generation and prior to itsuse in rendering the fourth image 1204. In some embodiments, the thirdimage is used to render the fourth image directly after the generationof the third image.

The false color used to replace the selected original color of the firstimage 1201 can be chosen to maximize contrast relative to other originalcolors of the first image. For example, if the first image is associatedwith a surgical wound bed or a surgical tissue, then a green color orblue color can be chosen as the false color. In this case, the green orblue false color provides relatively better contrast with the red colortones typically present in images of this subject type.

The false color of the third image 1203 used to replace the selectedoriginal color of the first image 1201 can be chosen to have a selectedhue, saturation, or value. In some embodiments, the false color of thethird image is chosen to have a color hue complementary to that of theselected original color of the first image. In some embodiments, thefalse color of the third image is chosen to have a color saturationdifferent from that of the selected original color of the first image.In some embodiments, the false color of the third image is chosen tohave a color value different from that of the selected original color ofthe first image. In some embodiments, the false color of the third imageis chosen to have a color value that is within the range between themaximum and minimum color values of all original colors of the firstimage. In some embodiments, the false color of the third image is chosento have a transparency such that it does not block relevant informationof the second image 1202 upon rendering of the composite fourth image1204.

The rendering of the fourth image 1204 is accomplished by overlaying thesecond image 1202 and the third image 1203. In some embodiments, thefourth image is a composite image that is stored subsequent to itsrendering and prior to its displaying. In some embodiments, the fourthimage is rendered with the use of a computer system and computationalalgorithm to digitally combine the second image and the third image increating a fourth image. In some embodiments, the fourth image isrendered by simultaneously displaying the second image and the thirdimage to create a superimposed fourth image.

The constructing of the fifth image 1205 is accomplished by overlayingthe first image 1201 and the second image 1202. In some embodiments, thefifth image is a composite image that is stored subsequent to itsrendering and prior to its displaying. In some embodiments, the fifthimage is constructed with the use of a computer system and computationalalgorithm to digitally combine the first image and the second image increating a fifth image. In some embodiments, the fifth image isconstructed by simultaneously displaying the first image and the secondimage to create a superimposed sixth image.

The fourth 1204 and fifth 1205 images are alternately presented on adisplay for viewing by the operator. The display can be a monitor, ascreen, a detector, an eyepiece, or any other visual interface. Thealternating display can dynamically enhance perceived contrast to helpthe human visual system better detect the signal and location of theflashing or flicking region of alternating color. This can beparticularly important for cases in which a low signal level wouldresult in a contrast within a static image that would be challenging fora user to ascertain with a required degree of certainty. In these cases,the flashing of complementary colors works to alleviate visualoverstimulation and loss of sensitivity, and to enhance perceivedcontrast.

The alternately displaying of any of the above methods can be performedat a selected frequency. The frequency can be chosen to correspond withranges appropriate for improving human visual perception. The frequencycan be further chosen to enhance visual sensitization. The frequency canbe, for example, between 0.1 Hz and 60 Hz, between 0.1 Hz and 30 Hz,between 15 Hz and 45 Hz, between 30 Hz and 60 Hz, between 0.1 Hz and 20Hz, between 10 Hz and 30 Hz, between 20 Hz and 40 Hz, between 30 Hz and50 Hz, between 40 Hz and 60 Hz, between, 0.1 Hz and 10 Hz, between 5 Hzand 15 Hz, between 10 Hz and 20 Hz, or between 15 Hz and 25 Hz. In someembodiments, the frequency of the alternately displaying is between 0.1Hz and 25 Hz.

The alternately displaying can be performed at a fixed selectedfrequency. The alternately displaying can be performed at a changingfrequency. The frequency changes can be used to indicate additionalinformation. The additional information can be related to, for example,the significance of information present in the alternately displayedimages, a warning, an identification, or other.

Any of the above methods can further comprise accepting operator inputselecting the frequency of the alternately displaying. Any of the abovemethods can further comprise accepting operator input selecting theviewpoint. Any of the above methods can further comprise acceptingoperator input selecting a region of an image. Operator input can beentered using any systems or methods effective for computer control. Insome embodiments, operator input is entered using key or button presses.In some embodiments, operator input is entered using voice commands. Insome embodiments, operator input is entered using accelerometers. Insome embodiments, operator input is entered using gestures. In someembodiments, operator input is entered using manipulation of one or morecontrol sticks. In some embodiments, operator input is entered usingtouch. The selection of a viewpoint using touch can comprise, forexample, pinch commands to select viewpoints closer to the subject, zoomcommands to select viewpoints farther from the subject, and/or swipegestures to select viewpoints rotated about the subject.

In some embodiments, the first image is a color map. In general, thereare three categories of color maps used for the visual presentation ofinformation. Nominal, or segmenting, color maps use different hues fordifferent nominal or non-orderable data. Sequential color maps typicallyuse changes in lightness and are commonly applied to the visualizationof rankable or orderable data, such as those having low, medium, andhigh levels. Diverging color maps can be used to split any meaningfulnumerical data at a mid-point to indicate two categories such aspositive and negative, or yes and no. In some embodiments, the firstimage is a color map having multiple colors. In some embodiments, thered, green, and blue components of the first image are each replacedwith their complementary hues in the generation of a false color image.

The terms “first”, “second”, “third”, “fourth”, “fifth”, and “sixth”when used herein with reference to images, colors, hues, saturations,values, wavelengths, or other elements or properties are simply to moreclearly distinguish the two or more elements or properties and are notintended to indicate order.

The terms “about” and “approximately equal” are used herein to modify anumerical value and indicate a defined range around that value. If “X”is the value, “about X” or “approximately equal to X” generallyindicates a value from 0.90X to 1.10X. Any reference to “about X”indicates at least the values X, 0.90X, 0.91X, 0.92X, 0.93X, 0.94X,0.95X, 0.96X, 0.97X, 0.98X, 0.99X, 1.01X, 1.02X, 1.03X, 1.04X, 1.05X,1.06X, 1.07X, 1.08X, 1.09X, and 1.10X. Thus, “about X” is intended todisclose, e.g., “0.98X.” When “about” is applied to the beginning of anumerical range, it applies to both ends of the range. Thus, “from about6 to 8.5” is equivalent to “from about 6 to about 8.5.” When “about” isapplied to the first value of a set of values, it applies to all valuesin that set. Thus, “about 7, 9, or 11%” is equivalent to “about 7%,about 9%, or about 11%.”

What is claimed is:
 1. A method of displaying images of a biological sample, the method comprising: receiving a first image representing a view from a viewpoint; selecting an original color from the first image, wherein the original color has a first hue; generating a second image from the first image by replacing the selected original color of the first image with a false color having a hue on an opposite side of a hue/saturation/value color space from the first hue; and alternately displaying the first and second images.
 2. The method of claim 1, wherein the first image has a minimum first image color value and a maximum first image color value, and wherein the false color has a false color value that is within the range between the minimum and maximum first image color values.
 3. The method of claim 1, wherein the alternately displaying is performed at a frequency.
 4. The method of claim 3, wherein the frequency of the alternately displaying is between 0.1 Hz and 25 Hz.
 5. The method of claim 3, further comprising: accepting operator input selecting the frequency of the alternately displaying.
 6. The method of claim 1, wherein the first image is a reflected light image, a fluorescence image, an X-ray image, a positron emission tomography (PET) image, a photon emission computed tomography (SPECT) image, a magnetic resonance imaging (MRI) image, a nuclear magnetic resonance (NMR) image, an ultrasound image, an autoradiography image, an immunohistochemistry image, or a microscopy image.
 7. The method of claim 1, further comprising: accepting operator input selecting the viewpoint.
 8. A machine-readable non-transitory medium embodying information indicative of instructions for causing a computer processor to perform operations for displaying images, the operations comprising: receiving a first image representing a view from a viewpoint; selecting an original color from the first image, wherein the original color has a first hue; generating a second image from the first image by replacing the selected original color of the first image with a false color having a hue on an opposite side of a hue/saturation/value space from the first hue; and alternately displaying the first and second images.
 9. The machine-readable non-transitory medium of claim 8, wherein the first image has a minimum first image color value and a maximum first image color value, and wherein the false color has a false color value that is within the range between the minimum and maximum first image color values.
 10. The machine-readable non-transitory medium of claim 8, wherein the alternately displaying is performed at a frequency.
 11. The machine-readable non-transitory medium of claim 10, wherein the frequency of the alternately displaying is between 0.1 Hz and 25 Hz.
 12. The machine-readable non-transitory medium of claim 10, wherein the operations further comprise: accepting operator input selecting the frequency of the alternately displaying.
 13. The machine-readable non-transitory medium of claim 8, wherein the operations further comprise: accepting operator input selecting the viewpoint.
 14. A computer system for displaying images, the system comprising: at least one processor, and a memory operatively coupled with the at least one processor, the at least one processor executing instructions from the memory comprising: program code for receiving a first image representing a view from a viewpoint; program code for selecting an original color from the first image, wherein the original color has a first hue; program code for generating a second image from the first image by replacing the selected original color of the first image with a false color having a hue on an opposite side of a hue/saturation/value color space from the first hue; and program code for alternately displaying the first and second images.
 15. The computer system of claim 14, wherein the first image has a minimum first image color value and a maximum first image color value, and wherein the false color has a false color value that is within the range between the minimum and maximum first image color values.
 16. The computer system of claim 14, wherein the alternately displaying is performed at a frequency.
 17. The computer system of claim 16, wherein the frequency of the alternately displaying is between 0.1 Hz and 25 Hz.
 18. The computer system of claim 16, wherein the instructions executed by the at least one processor further comprise: accepting operator input selecting the frequency of the alternately displaying.
 19. The computer system of claim 14, wherein the instructions executed by the at least one processor further comprise: accepting operator input selecting the viewpoint. 